Population Genetics and Dynamics of Caribbean Spiny Lobster (Panulirus argus) Phyllosoma in the Sargasso Sea Jody Daniel1,2, Jeremy Pivor1,3 1 Sea Education Association, 2 St. George’s University, St. Georges, Grenada, 3 Washington University in St. Louis, St. Louis, Missouri Abstract: Results/Discussion Continued: The Caribbean Spiny Lobster, Panulrius argus, is widely distributed across the Atlantic Ocean and its Results/Discussion: fishery is ranked as the second most economically important in the Central Atlantic region. Stocks have been decreasing since the early 21st century. Management of the fishery has been difficult given the wide Puerulus 4 Fig. 8: Life stages and genetic uncertainty regarding Spiny Lobster population dynamics. The long-range dispersal of the planktonic 4% lineages of phyllosoma collected larvae, called phyllosoma, makes it difficult to determine P. arg us population structuring. Uncertainty X V at each station across latitude regarding local or distant recruitment of lobster stocks has made it difficult to create management IX 3% 7% 18% 3 from St. Croix to Bermuda during strategies. The Sargasso Sea may serve as critical habitat for phyllosoma in acting as a corridor between cruise C241. Highest life stages 19851991 stocks in the Gulf of Mexico, Florida, South America, and the Caribbean. In our study we have explored the (9 and 10) were collected in influence of selected environmental parameters on phyllosoma distribution, as well as genetic and life stage 2 19921998 VI northern latitudes. Life stage structuring in the Sargasso Sea in order to understand Panulirus argus population dynamics. We found no VIII 14% 19992005 structuring was relatively significance between phyllosoma abundance and temperature, salinity, or chlorophyll a concentration. 25% 20062012 heterogeneous across the Examination of historical records from Sea Education Association 1979-2012 cruises and our data in the 1 CollectedperStation transect. Station 012 contained o o Average#ofPhyllosoma Sargasso Sea revealed a narrow temperature range in which phyllosoma were found (18.0 -28.3 C). the greatest heterogeneity in life Additionally, the temporal variations of phyllosoma abundance from Sea Education Association archived VII 0 stages. The figure shows that data from 1985-2012 in the North and South Sargasso Sea was relatively variable. Life stage structuring 29% South North 75% were associated with and genetic analysis of the phyllosoma collected, and previously sequenced adults from Diniz et. al. 2005, evolutionary linage 1 and 25% (357bp) supports the Pan-Caribbean Panmictic theory of distant recruitment. This suggests the need for Fig. 3: Proportion of phyllosoma P. argus Fig. 4: Average phyllosoma collected at each were related to evolutionary regional management of the Caribbean Spiny Lobster. life stages collected from St. Croix to station between 1985-2012 in the South and North linage 2. Station 012 contained Bermuda (n=27). Figure shows that life Sargasso Sea. Figure shows that the average phyllosoma of both lineages 1 stages 8 and 7 constituted 54% of the P. abundance of phyllosoma collected is highly and 2. There were no genetic Background: argus collected, while no phyllosoma below variable. patterns found with increasing life stage 5 were found latitude. •The Caribbean Spiny Lobster, Panulirus argus, population structuring is complicated by the long-range dispersal of the planktonic larvae, called 50 500 phyllosoma. 45 450 •Two theories of recruitment have been postulated, the Pan-Caribbean 40 400 35 350 Panmictic theory (Lyons 1980) and the Closed System Theory (Menzies et 30 300 25 y=1.6286xR 30.666 250 al. 1979). R²=0.0617 •The Sargasso Sea may serve as critical habitat in acting as a corridor 20 p=0.1447 200 15 150 NumberofPhyllosoma NumberofPhyllosoma between distant populations. 10 100 5 50 0 0 20.0 21.0 22.0 23.0 24.0 25.0 26.0 27.0 28.0 29.0 0.0 10.0 20.0 30.0 40.0 Purpose: Seasurfacetemperature(°C) SeaSurfaceTemperature(°C) SSV To investigate the influence of selected environmental parameters on Fig. 5: Number of phyllosoma collected along Fig. 6: Number of phyllosoma collected along Corwith Cramer phyllosoma distribution, as well as genetic and life stage structuring in the Sea Education Association cruises from 2010- SEA Education Association cruises from 1979- Sargasso Sea in order to understand Panulirus argus population dynamics. 2012 (diamond) in the Sargasso Sea, including P. 2012 in the Sargasso Sea with respect to sea argus from cruise C241 (St. Croix to Bermuda) surface temperature. Figure shows an (square), with respect to sea surface temperature. observed ecological trend of greater Figure shows that phyllosoma abundance from phyllosoma abundance within a narrow Methods: C241 was observed to peak at 26.3oC and temperature range of 18.0o-28.3oC. Conclusions: o •Phyllosoma were collected aboard the SSV Corwith Cramer research cruise ranged from 24.2-26.4 C •Distribution of phyllosoma may be limited or impacted by sea surface temperature. between May 14th – June 17th 2012 from St. Croix to Woods Hole, •Further analysis on the possible impact of salinity and chlorophyll a concentration are Fig. 7: Maximum Likelihood tree Massachusetts via Bermuda. describing evolutionary relationships required. among 32 P. argus haplotypes from (24 •The temporal variations of phyllosoma abundance in the North and South Sargasso •A neuston net and meter net adults) Diniz et al 2005 and 8 phyllosoma (1 from C230A and 7 from C241) Sea may be related to adult population dynamics or distant spawning events during the (~10m below the surface) were deployed at (highlighted), resolved on the basis of reproductive season, but do not match the decreasing trend of adult stocks. 0000 daily along a 1 nautical mile transect (357bp) HV-CRd1. Bootstrap values •Genetic analysis and life stage structuring from our study supports the Pan-Caribbean Lineage 1 based on 1000 replicates representing all at 2 knots (Fig. 1). nodes. The tree shows that phyllosoma Panmictic theory versus the Closed System theory. collected had similar genetic structuring to •Temperature, salinity, and chlorophyll a previously sequenced adults. No phyllosoma were genetically similar to the Policy Implications: fluorescence were measured Brazil population. The figure also shows Given the observed mixing of populations, and therefore support for the distant along the ship’s path. Fig. 1: Neuston net deployment indiscrete population structuring of phyllosoma within lineages 1 and 2. recruitment theory, a regional fisheries management approach may be a feasible option for the Caribbean Spiny Lobster fishery. Further research though is needed to •Phyllosoma were classified to species and determine stock origins in order to enable more specific regional collaboration. life stage using the body length (BL), cephalic shield length (CL), cephalic shield width (CW), thorax width (TW), and Acknowledgments: microscopy (Fig. 2). The authors are thankful to the Sea Education Association for providing the transportation and equipment needed to carry out this research. We are also grateful to Dr. Amy Suida, Dr. Erik Zettler, Dr. Linda Amaral-Zettler and Ms. Annie Scoffield for their insightful Lineage 2 advice and assistance during the study and data analysis period. We are also thankful to the crew of the SSV Corwith Cramer and the •Neural and muscle tissue were used for DNA C-241 class for their support during our project (especially the cool, calm, collected C watch). Lastly, we are grateful to Mr. Greg Boyd and the Bermuda Aquarium, Natural History Museum and Zoo for providing us with neural tissue samples from adult lobsters for genetic extraction and sequenced using the analysis. hypervariable domain of the mitochondrial DNA control region (HV-CRd1) with the References: primers CRL-F and CRL-R. •Diniz, F.M., N. Maclean, M. Ogawa, I.H.A. Cintra, AND P. Bentzen. 2005. The hypervariable domain of the mitochondrial control region in Atlantic spiny lobsters and its potential as a marker for investigating phylogeographic structuring. Mar. Biotech. Brazil 7: 462-473, doi: 10.1007/s10126-004-4062-5. •23 samples were sent for DNA sequencing, Fig. 2: Diagram showing •Goldstein, J. S., H. Matsuda, T. Takenouchi, AND M. J. Butler IV. 2008. The complete development of larval Caribbean spiny and consensus reeds with an 85% identity measurements of Panulirus argus lobster Panulirus argus in culture. J. Crustacean Biol. 28: 306-327. phyllosoma. (Goldstein et al. 2008) •Lyons, W. G. 1980. Possible sources of Florida’s spiny lobster population. Proc. Gulf Caribb. Fish. Inst. 33: 253-266. to P. argus were used for analysis. •Menzies, R.A., and, J.M, Kerrigan.1979. Implications of spiny lobster recruitment patterns of the Caribbean – A biochemical genetic approach. Proc. Gulf Caribb. Fish. Inst. 31: 164-178. Funding to support this work was provided by NSF-TUES grant DUE-1043468 Biodiversity of hydroid communities associated with pelagic Sargassum Kiah Walker1, 2 and Allison Work1, 3 1Sea Education Association, Woods Hole, MA, 2Williams College, Williamstown, MA, 3Whitman College, Walla Walla, WA Abstract Results and Discussion Marine hydroids (Cnidaria, Hydrozoa) live in both coastal and open ocean regions throughout the world. In the Sargasso Sea, hydroids colonize the 100% two types of pelagic Sargassum, Sargassum fluitans and S. natans. This study assessed species diversity and geographic distribution of hydroids 90% living on these substrates. Hydroids were collected along a cruise track 80% from Puerto Rico to Bermuda and Bermuda to New York during April and 70% May 2014. Hydroids were identified morphologically, and forty samples A. latecarinata were analyzed using sequences from the 16S ribosomal RNA gene. Hydroid 60% C. noliformis species composition differed between the two species of Sargassum, as 50% H. diaphana a b four hydroid species were found on both types of Sargassum, and two Occurred Occurred 40% L. flexuosa were exclusive to S. natans. Aglaophenia latecarinata was the dominant O. dichotoma species on S. fluitans, while Clytia noliformis was the dominant species on 30% P.